Add JDBI SQL Object integration test support.

This changeset adds a simple base class for implementing JDBI integration tests. 

Extending `JdbiIntegrationTest` allows you to quickly get instances of JDBI SQL Objects for testing. When run, the tests will first execute your migrations to ensure the state of your database is clean and consistent – this also ensures that the queries in your SQL Object are tested against the same schema used to create your production database.

Note: this implementation does assume that users are using migrations in their service.